Git

Git integration for PowerShell Universal.

Git integration requires a license.

PowerShell Universal is capable of synchronizing the configuration scripts with a remote git repository.

Configuration

Database

Git sync can be configured in the database. This is the preferred approach when using SQL persistence. The benefit is that when you connect new instances of PowerShell Universal to your SQL instance, you will not need to configure git sync again.

To configure git sync, navigate to Settings \ Git within the Admin Console. You will be able to click the Git Settings button.

appsettings.json

You can also use the Configuration settings to setup git sync. This is useful if you have a single instance of PSU and would like to back up your appsettings.json file.

Git Sync Settings

Use Database

This feature requires a git client installed on each PowerShell Universal server.

To avoid having to use an external git service like GitHub or Gitlab, you can use the PowerShell Universal database. Git synchronization will produce a git bundle and upload it to the SQL database. Other nodes within your cluster will pull the git bundle and update their configuration based on the bundle rather than a remote git fork.

Branch

By default, PowerShell Universal will sync with the master branch. If you wish to use a different branch, specify the GitBranch setting within your appsettings.json.

Authentication

You will need to configure authentication to your remote git repository. We recommend a personal access token.

External Git Client

You can choose to use an external git client rather than using the library built into PowerShell Universal. This allows you additional configuration options such as using SSH authentication. PowerShell Universal will not use configured username, passwords or PATs when enabling this method. You will need to have a git client installed.

Setting Credentials

When using the external git client, you are responsible for configuring credentials before performing a synchronization.

You can configure credentials via git configuration or the URL passed to PowerShell Universal.

The following command will store the credentials in plaintext on the PowerShell Universal server. You will need to run this command as the service account user so that they have access to the credentials. This will create a .git-credentials file that will be used when authenticating against the target URL. You may need to change the URL depending on your git remote.

git config --global credential.helper store
echo "https://${username}:${password_or_access_token}@github.com" > ~/.git-credentials

You can also store credentials directly in the URL provided to PowerShell Universal.

https://adam:APP_TOKEN@github.com/myOrg/myRepo.git

Example: User Name and PAT

To use an external git client and pass a user name and PAT to authenticate with, you can specify them in the git remote URL. For example:

https://username:PAT@github.com/ironmansoftware/universal

Example: SSH and GitHub

First, you will need to configure your local ssh-agent and GitHub account with SSH keys.

You can follow their guide here.

Next, you will provide a SSH URI for the git remote URL in PowerShell Universal. The configured SSH key will be used for the connection.

git@github.com:ironmansoftware/universal.git

SSL Certificate Problem

SSL Certificate problem: unable to get local issuer certificate

If you are running on Windows and receive an SSL Certificate problem, you may need to ensure that you have enabled schannel support.

Credential Persistence

Unable to persist credentials with the 'wincredman' credential store.

If you are on Windows and receive an error about persisting credentials in wincredman, you may need to set the credential persistence to DAPI. You can learn how to do that here.

Manual Mode

Manual mode requires users editing the PowerShell Universal instance to click Edit in order to make changes in the system.

Once the changes are complete, the user can then click Save Changes to begin a commit

On the git commit page, you can view the changed files and enter a commit message.

Once changes have been committed, they will be pushed to the remote and the service will start to synchronize with git again. There is also a chance that a git merge conflict can take place at this time. See Dealing with Conflicts for more information.

Manual mode can be set in the git settings within the admin console or within appsettings.json.

"Data": {
  "RepositoryPath": "%ProgramData%\\UniversalAutomation\\Repository",
  "ConnectionString": "filename=%ProgramData%\\UniversalAutomation\\database.db;upgrade=true",
  "RunMigrations": true,
  "GitRemote": "",
  "GitUserName": "",
  "GitPassword": "",
  "GitBranch": "",
  "GitSyncBehavior": "TwoWay",
  "GitInitializeBehavior": "",
  "GitSyncInterval": "1",
  "ConfigurationScript": "",
  "Mode": "Manual" // Or Automatic
},

Method One: Pushing Local Files to Remote

The default location for the local repository is C:\ProgramData\UniversalAutomation\Repository

You must ensure that your local folder is not a pre-existing git repository. Your repository directory should be simply a folder with your PowerShell Universal files. If a .git folder exists, and you do not wish to use this repository, you should delete it and PowerShell Universal will create a new repository.

If you are populating a new git repository, you need to ensure that the remote does not have any files in it. It should be a completely bare repository. For example, when creating a repository on GitHub, do not select a license or readme.md file to be created.

Once the repository has been created, you can retrieve the git remote URL and provide that to the PowerShell Universal appsettings.json file.

Once you have the branch, git remote URL and credentials, you can provide them to your appsettings.json file and the git remote will be populated with your local files.

Method Two: Pulling from a Git Remote

The default location for the local repository is C:\ProgramData\UniversalAutomation\Repository

You can configure PowerShell Universal to pull from a git remote. In this configuration, you must ensure that your local repository folder is completely empty. Any files within the folder will cause the git sync to fail and prevent it from recovering.

Configure the appsettings.json file to include the branch, credentials and git remote URL that you are cloning. Once the fields have been set, you can start the PowerShell Universal service. The first thing the service will do is clone the repository and configure it locally.

Included Files

The files that are included with a git sync are any files within the local repository. This includes PS1 configuration files, pages XML files and any other files you may add manually.

The following are not included:

  • appsettings.json

  • database.db

  • web.config

  • PowerShell Universal Application Binaries

Git History and Status Page

The history tab displays all the git commit history for the current repository.

The sync status tab displays the current status of nodes within the PSU cluster.

Testing Git Sync

The best way to ensure that your git sync is working properly is to click the Synchronize Now button. This will force a sync to run, and you can verify whether the settings entered worked properly.

Viewing Changes

You can view changes within the table of git syncs. Each sync includes the number of changes found since the last sync, the SHA of the commit and a list of changes between that SHA and the previous one. When files are in a modified state, you will be able to view the diffs using the file diff tool.

Dealing with Conflicts

Conflict resolution is only available in manual git sync mode.

When multiple users are editing the PowerShell Universal configuration files, there may be conflicts. PowerShell Universal will display that a particular node is in a conflicted state when attempting to commit changes. You will see a list of changes that are conflicted on the git commit page. Click the Resolve Conflict button to view the conflict in an editor.

In this example, the string for this endpoint was edited on both the remote and the local repository.

Edit the text to remove the conflict.

Save the changes and navigate back to the git commit page. Enter a new commit message for the merge conflict and click Commit Changes.

This will resolve the merge conflict and push to the remote.

Git Synchronization Behavior

Two-Way

By default, git synchronization will work both ways. If you make changes within the PSU admin console, those changes will be committed and sync'd to the configured remote.

Any changes that are made in the remote will be pulled locally.

If you setup git sync with a preexisting git remote, the changes will be pulled and synchronized locally. You cannot have any changes locally.

If you setup git sync with a bare repository, the local changes will be sync'd and the repository will be initialized.

One-Way

You can adjust the git synchronization behavior by changing the GitSyncBehavior setting in appsettings.json. When set to OneWay, the admin console and management API will become read-only. The PowerShell Universal system will pull from the remote but will never push or commit locally.

    "Data": {
    "RepositoryPath": "%ProgramData%\\UniversalAutomation\\Repository",
    "ConnectionString": "%ProgramData%\\UniversalAutomation\\database.db",
    "DatabaseType": "LiteDB",
    "GitRemote": "https://github.com/myorg/myrepo.git",
    "GitUserName": "any",
    "GitPassword": "MYPAT----------------"
    "GitBranch": "dev",
    "GitSyncBehavior": "OneWay",
    "ConfigurationScript": ""
  },

Push-Only

Push-only git sync mode will not pull changes from the remote. Any changes made locally will be pushed up to the remote. The console will not be read-only. This configuration is useful for scenarios where you have one machine that is used to for the source-of-truth configuration for a pool of servers that are read-only.

"Data": {
  "RepositoryPath": "%ProgramData%\\UniversalAutomation\\Repository",
  "ConnectionString": "%ProgramData%\\UniversalAutomation\\database.db",
  "DatabaseType": "LiteDB",
  "GitRemote": "https://github.com/myorg/myrepo.git",
  "GitUserName": "any",
  "GitPassword": "MYPAT----------------"
  "GitBranch": "dev",
  "GitSyncBehavior": "PushOnly",
  "ConfigurationScript": ""
},

Git Initialization Behavior

Defines the git initialization behavior. If this parameter is not set, PowerShell Universal will attempt to select the proper method based on the state of the local file system.

Clone

Clones the remote to the local repository folder. The local folder must be empty.

  "Data": {
    "RepositoryPath": "%ProgramData%\\UniversalAutomation\\Repository",
    "ConnectionString": "%ProgramData%\\UniversalAutomation\\database.db",
    "DatabaseType": "LiteDB",
    "GitRemote": "https://github.com/myorg/myrepo.git",
    "GitUserName": "any",
    "GitPassword": "MYPAT----------------"
    "GitBranch": "dev",
    "GitSyncBehavior": "OneWay",
    "GitInitializationBehavior": "clone",
    "ConfigurationScript": ""
  },

Init

Initializes the local repository and pushes it to the remote. The remote must be bare.

  "Data": {
    "RepositoryPath": "%ProgramData%\\UniversalAutomation\\Repository",
    "ConnectionString": "%ProgramData%\\UniversalAutomation\\database.db",
    "DatabaseType": "LiteDB",
    "GitRemote": "https://github.com/myorg/myrepo.git",
    "GitUserName": "any",
    "GitPassword": "MYPAT----------------"
    "GitBranch": "dev",
    "GitSyncBehavior": "OneWay",
    "GitInitializationBehavior": "init",
    "ConfigurationScript": ""
  },

Personal Access Token

We recommend that you use a personal access token (PAT) over a user name and password. You can configure a personal access token by setting the password property in the appsettings.json or other configuration methods.

    "Data": {
    "RepositoryPath": "%ProgramData%\\UniversalAutomation\\Repository",
    "ConnectionString": "%ProgramData%\\UniversalAutomation\\database.db",
    "GitRemote": "https://github.com/myorg/myrepo.git",
    "GitUserName": "any",
    "GitPassword": "MYPAT----------------"
  },

In GitHub, you can retrieve a personal access token by clicking your avatar in the top right, selecting Settings, Developer Settings and then Personal Access Tokens.

When generating your access token, ensure that you select the Repo permissions.

Note, that if you are using BitBucket, you will need to specify the user name in addition to the PAT in appsettings.json.

User name and password

You can also configure a git remote to authenticate with a user name and password. Set the user name and password either with the appsettings.json file or another configuration method.

    "Data": {
    "RepositoryPath": "%ProgramData%\\UniversalAutomation\\Repository",
    "ConnectionString": "%ProgramData%\\UniversalAutomation\\database.db",
    "GitRemote": "https://github.com/myorg/myrepo.git",
    "GitUserName": "myusername",
    "GitPassword": "mypassword"
  },

Benefits of Git Sync vs Manual Git Sync

It is possible to manually git sync a repository. PowerShell Universal uses very basic commands when dealing with git. Any changes made to PowerShell Universal through the admin console or API invoke a git commit and the author is set to the identity of the user making the change. During a git sync operation, we first perform a git pull to ensure that we have the latest version of files on the remote. Next, we perform a git push to push up local commits that have happened since the last sync.

You could achieve this functionality with a scheduled job.

That said, one feature of the git sync is that it analyzes the commit to ensure that only files that were changed during the sync are reloaded. This will stop dashboards from auto-deploying when they haven't changed or APIs services from restarting when environments haven't been updated. So there is a performance gain here.

The other issue is that due to the way that PowerShell Universal watches files (with a FileSystemWatcher) and the way that git updates files, the configurations will not reload automatically after a pull. You will have to ensure that you force the configurations to be reevaluated.

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